db_version /var/tmp//ccA79QxQ.o
db_env_create /var/tmp//ccA79QxQ.o
ld: fatal: Symbol referencing errors. No output written to conftest
collect2: ld returned 1 exit status
configure: failed program was:
#line 18111 "configure"
#include "confdefs.h"
...
which indicated the configure script didn't automatically add -ldb to tell the compiler to actually USE the Berkeley database althought it certainly detected it (enough to make the mismatch error).
So, in addition to the good advice on the Internet from everyone to use CC, CFLAGS, CPPFLAGS, and LDFLAGS, I needed to explicitly define LIBS. (More on this in a sec.)
setenv LIBS -ldb

Lastly, I also saw a cross compile error:
checking for LinuxThreads consistency... no
checking if pthread_create() works... yes
checking if select yields when using pthreads... cross
configure: error: crossing compiling: use --with-yielding_select=yes|no|manual
I turned off cross compiling in the configuration step.